Rear lateral blind-spot warning system and method for vehicle

ABSTRACT

A rear lateral blind-spot warning system for a vehicle includes a sensor configured to sense position information and movement information on an external obstacle, a determiner configured to determine the type of the external obstacle located in a rear blind spot or a lateral blind spot of the vehicle based on the position information and the movement information sensed by the sensor, a setter configured to set a rear lateral blind-spot warning range or a rear lateral blind-spot warning time based on the type of the external obstacle determined by the determiner, and a controller configured to control rear lateral blind-spot warning operation based on the rear lateral blind-spot warning range or the rear lateral blind-spot warning time set by the setter.

CROSS-REFERENCE TO THE RELATED APPLICATION

This application is the continuation application of U.S. patentapplication Ser. No. 17/408,775, filed on Aug. 23, 2021, which claimspriority from Korean Patent Application No. 10-2020-0110288, filed onAug. 31, 2020, in the Korean Intellectual Property Office, thedisclosures of which are incorporated herein by reference in theirentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a rear lateral blind-spot warningsystem, and more particularly to a technology for recognizing whether avehicle located in a rear blind spot or a lateral blind spot of a hostvehicle is a large vehicle and controlling a rear lateral blind-spotwarning system based on the result of the recognition.

2. Description of the Related Art

A rear lateral blind-spot warning system is a system that senses avehicle approaching a lateral blind spot or a rear blind spot of a hostvehicle and announces this situation in advance. Most rear lateralblind-spot warning systems utilize an ultrasonic sensor or a radarsensor in order to sense objects present in the vicinity of a hostvehicle.

However, a conventional rear lateral blind-spot warning system is notcapable of recognizing whether a vehicle present in a lateral blind spotor a rear blind spot of a host vehicle is a passenger car or a largevehicle. Further, the conventional rear lateral blind-spot warningsystem recognizes a large vehicle using a detection range set for apassenger car, and thus prematurely terminates the rear lateralblind-spot warning operation in the case where a large vehicle remainsin the rear blind spot or the lateral blind spot of the host vehicle.

The information disclosed in this Background section is only forenhancement of understanding of the general background of the presentdisclosure, and should not be taken as an acknowledgement or any form ofsuggestion that this information forms the related art already known toa person skilled in the art.

SUMMARY

Therefore, the present disclosure has been made in view of the aboveproblems, and it is an object of the present disclosure to provide arear lateral blind-spot warning system and method capable of recognizingwhether an external obstacle located in a rear blind spot or a lateralblind spot of a host vehicle is a passenger car or a large vehicle andof, when the external obstacle is determined to be a large vehicle,increasing a rear lateral blind-spot warning range or a rear lateralblind-spot warning time, thereby accurately recognizing the largevehicle located in the rear blind spot or the lateral blind spot of thehost vehicle and accurately announcing the result of recognition to adriver.

In accordance with an aspect of the present disclosure, the above andother objects can be accomplished by the provision of a rear lateralblind-spot warning system for a vehicle, including a sensor configuredto sense position information and movement information on an externalobstacle, a determiner configured to determine the type of the externalobstacle located in a rear blind spot or a lateral blind spot of thevehicle based on the position information and the movement informationsensed by the sensor, a setter configured to set a rear lateralblind-spot warning range or a rear lateral blind-spot warning time basedon the type of the external obstacle determined by the determiner, and acontroller configured to control rear lateral blind-spot warningoperation based on the rear lateral blind-spot warning range or the rearlateral blind-spot warning time set by the setter.

The sensor may sense the position information or the movementinformation on the external obstacle located in the rear blind spot orthe lateral blind spot of the vehicle using a radar sensor installed inthe vehicle.

The sensor may sense the position information on the external obstaclethrough sensed detection points.

The determiner may form a predetermined tracking range based oninitially sensed detection points and may determine whether the externalobstacle is a passenger car or a large vehicle based on detection pointslocated within the predetermined tracking range among the initiallysensed detection points.

The determiner may calculate the number of detection points, based onsensing information sensed by the sensor and the movement information orposition information on the external obstacle, and may determine thatthe external obstacle is a large vehicle when the number of thedetection points located within the predetermined tracking range isgreater than or equal to the calculated number of detection points.

The determiner may determine that the external obstacle is a largevehicle when the number of the detection points located within thepredetermined tracking range is greater than or equal to a predeterminednumber.

The determiner may obtain an individual bit frequency componentproportional to the distance by performing an FFT operation on a sensingsignal of the sensor, may obtain a Doppler frequency componentproportional to the speed by performing the FFT operation on theindividual bit frequency component, and may calculate the averagefrequency power of a warning region based on the distance and the speed,determined using the individual bit frequency component and the Dopplerfrequency component.

The determiner may determine that the external obstacle is a largevehicle when the average frequency power of the warning region isgreater than or equal to a predetermined power value.

When the determiner determines that the external obstacle is a largevehicle, the setter may increase the rear lateral blind-spot warningrange such that the same is greater than a predetermined range.

When the determiner determines that the external obstacle is a largevehicle, the setter may increase the rear lateral blind-spot warningtime such that the same is greater than a predetermined time.

In accordance with another aspect of the present disclosure, there isprovided a rear lateral blind-spot warning method for a vehicle,including a sensing step of sensing position information and movementinformation on an external obstacle, a determination step of determiningthe type of the external obstacle located in a rear blind spot or alateral blind spot of a vehicle based on the position information andthe movement information sensed in the sensing step, a setting step ofsetting a rear lateral blind-spot warning range or a rear lateralblind-spot warning time based on the type of the external obstacledetermined in the determination step, and a control step of controllingrear lateral blind-spot warning operation based on the rear lateralblind-spot warning range or the rear lateral blind-spot warning time setin the setting step.

The sensing step may include sensing the position information or themovement information on the external obstacle located in the rear blindspot or the lateral blind spot of the vehicle using a radar sensorinstalled in the vehicle.

The sensing step may include sensing the position information on theexternal obstacle through sensed detection points.

The determination step may include forming a predetermined trackingrange based on initially sensed detection points and determining whetherthe external obstacle is a passenger car or a large vehicle based ondetection points located within the predetermined tracking range amongthe initially sensed detection points.

The determination step may include calculating the number of detectionpoints, based on sensing information and the movement information orposition information on the external obstacle sensed in the sensingstep, and determining that the external obstacle is a large vehicle whenthe number of the detection points located within the predeterminedtracking range is greater than or equal to the calculated number ofdetection points.

The determination step may include determining that the externalobstacle is a large vehicle when the number of the detection pointslocated within the predetermined tracking range is greater than or equalto a predetermined number.

The determination step may include obtaining an individual bit frequencycomponent proportional to the distance by performing an FFT operation ona sensing signal of a sensor, obtaining a Doppler frequency componentproportional to the speed by performing the FFT operation on theindividual bit frequency component, and calculating the averagefrequency power of a warning region based on the distance and the speed,determined using the individual bit frequency component and the Dopplerfrequency component.

The determination step may include determining that the externalobstacle is a large vehicle when the average frequency power of thewarning region is greater than or equal to a predetermined power value.

The setting step may include increasing the rear lateral blind-spotwarning range such that the same is greater than a predetermined rangewhen the external obstacle is determined to be a large vehicle in thedetermination step.

The setting step may include increasing the rear lateral blind-spotwarning time such that the same is greater than a predetermined timewhen the external obstacle is determined to be a large vehicle in thedetermination step.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a diagram showing the configuration of a rear lateralblind-spot warning system for a vehicle according to an embodiment ofthe present disclosure;

FIGS. 2 to 5 are diagrams showing the case in which a conventional rearlateral blind-spot warning system fails to accurately sense a largevehicle;

FIG. 6 is a diagram showing the case in which the rear lateralblind-spot warning system for a vehicle according to the embodiment ofthe present disclosure senses a large vehicle using detection points;

FIGS. 7 to 10 are diagrams showing the case in which the rear lateralblind-spot warning system for a vehicle according to the embodiment ofthe present disclosure senses a large vehicle using average power withina position range and a speed range using FFT conversion; and

FIG. 11 is a flowchart showing a rear lateral blind-spot warning methodfor a vehicle according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various exemplary embodiments will now be described more fully withreference to the accompanying drawings, in which only some exemplaryembodiments are shown. Specific structural and functional detailsdisclosed herein are merely representative for the purpose of describingexemplary embodiments. The present disclosure, however, may be embodiedin many alternative forms, and should not be construed as being limitedto the exemplary embodiments set forth herein.

Accordingly, while exemplary embodiments of the present disclosure arecapable of being variously modified and taking alternative forms,embodiments thereof are shown by way of example in the drawings and willherein be described in detail. It should be understood, however, thatthere is no intent to limit the present disclosure to the particularexemplary embodiments disclosed. On the contrary, exemplary embodimentsare to cover all modifications, equivalents, and alternatives fallingwithin the scope of the invention.

It will be understood that, although the terms “first”, “second”, etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of exemplary embodiments ofthe present disclosure.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element, or intervening elements maybe present. In contrast, when an element is referred to as being“directly connected” or “directly coupled” to another element, there areno intervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g. “between” versus “directly between”, “adjacent” versus “directlyadjacent”, etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exemplaryembodiments of the present disclosure. As used herein, the singularforms “a”, “an”, and “the”, are intended to include the plural forms aswell, unless the context clearly indicates otherwise. It will be furtherunderstood that the terms “comprises”, “comprising”, “includes”, and/or“including”, when used herein, specify the presence of stated features,integers, steps, operations, elements, components, or combinationsthereof, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components, orcombinations thereof.

Unless otherwise defined, all terms used herein, which include technicalor scientific terms, have the same meanings as those generallyappreciated by those skilled in the art. The terms, such as ones definedin common dictionaries, should be interpreted as having the samemeanings as terms in the context of pertinent technology, and should notbe interpreted as having ideal or excessively formal meanings unlessclearly defined in the specification.

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. In thedrawings, the same reference numerals refer to the same components.

A sensor 10, a determiner 20, a setter 30, and a controller 40 accordingto an exemplary embodiment of the present disclosure may be implementedthrough a processor (not shown) configured to execute the operations tobe described below using a nonvolatile memory (not shown), which isconfigured to store an algorithm for controlling the operation ofvarious components of a vehicle or data related to a software commandfor executing the algorithm, and using data stored in the correspondingmemory. Here, the memory and the processor may be implemented asrespective chips. Alternatively, the memory and the processor may beimplemented as a single integrated chip. The processor may alternativelytake the form of one or more processors.

FIG. 1 is a diagram showing the configuration of a rear lateralblind-spot warning system of a vehicle 100 according to an embodiment ofthe present disclosure. FIGS. 2 to 5 are diagrams showing the case inwhich a conventional rear lateral blind-spot warning system fails toaccurately sense a large vehicle. FIG. 6 is a diagram showing the casein which the rear lateral blind-spot warning system of the vehicle 100according to the embodiment of the present disclosure senses a largevehicle using detection points. FIGS. 7 to 10 are diagrams showing thecase in which the rear lateral blind-spot warning system of the vehicle100 according to the embodiment of the present disclosure senses a largevehicle using average power within a position range and a speed rangeusing FFT conversion.

Hereinafter, an exemplary embodiment of the rear lateral blind-spotwarning system of the vehicle 100 according to the present disclosurewill be described with reference to FIGS. 1 to 10 .

As shown in FIGS. 2 to 5 , in the case of the conventional rear lateralblind-spot warning system, when an external obstacle 200 located in therear blind spot or the lateral blind spot of the vehicle 100 is a largevehicle, the large vehicle appears to be outside the rear lateral blindspot detection range due to the size thereof. Therefore, even when thelarge vehicle remains in the rear blind spot or the lateral blind spotof the vehicle 100, the conventional rear lateral blind-spot warningsystem incorrectly determines that the large vehicle is out of thedetection range, and terminates the rear lateral blind-spot warningoperation. Herein, “a large vehicle” according to an embodiment of thepresent disclosure may refer to a vehicle have a size larger than apredetermined size. For example, the size of the large vehicle may belarger than the size of, e.g., a passenger car or a motorcycle.

A rear lateral blind-spot warning system of the vehicle 100 according tothe present disclosure includes a sensor 10 configured to sense positioninformation and movement information on the external obstacle 200, adeterminer 20 configured to determine the type of external obstacle 200located in the rear blind spot or the lateral blind spot based on theposition information and the movement information sensed by the sensor10, a setter 30 configured to set a rear lateral blind-spot warningrange or a rear lateral blind-spot warning time based on the type ofexternal obstacle 200 determined by the determiner 20, and a controller40 configured to control the rear lateral blind-spot warning operationbased on the rear lateral blind-spot warning range or the rear lateralblind-spot warning time set by the setter 30.

According to one embodiment of the present disclosure, the rear lateralblind-spot warning system of the vehicle 100 may include a processor.The processor may have an associated non-transitory memory storingsoftware instructions which, when executed by the processor, providesthe functionalities of the determiner 20 and/or the setter 30. Theprocessor may take the form of one or more processor(s) and associatedmemory storing program instructions, and in some examples the one ormore processor(s) may be used to implement the functions of both theprocessor and the controller 40.

The sensor 10 may sense position information or movement information onthe external obstacle 200 located in the rear blind spot or the lateralblind spot of the vehicle 100. The external obstacle 200 may be anothervehicle, a motorcycle, or the like that is traveling behind the vehicle100. The position information is information regarding data on therelative positions of the external obstacle 200 and the vehicle 100, andthe movement information is information regarding data on the relativespeeds of the vehicle 100 and the external obstacle 200.

The determiner 20 may determine the size of the external obstacle 200based on the position information or the movement information on theexternal obstacle 200 sensed by the sensor 10, and may determine thetype of external obstacle 200, for example, whether the externalobstacle 200 is a large vehicle or a passenger car.

When the determiner 20 determines that the external obstacle 200 is alarge vehicle, the setter 30 may set the rear lateral blind-spot warningtime such that the entire body of the large vehicle is sensed for apredetermined increased time period, and may set the rear lateralblind-spot warning range such that the entire body of the large vehicleis sensed within a predetermined increased range.

The controller 40 may control the rear lateral blind-spot warningoperation based on the rear lateral blind-spot warning time or the rearlateral blind-spot warning range set by the setter 30.

Accordingly, when a large vehicle is located in the rear blind spot orthe lateral blind spot of the vehicle 100, it is possible to minimize orprevent the likelihood of a collision between the vehicle 100 and thelarge vehicle due to termination of a blind spot warning signal in thestate in which the large vehicle remains in the rear blind spot or thelateral blind spot of the vehicle 100.

The sensor 10 senses the position information or the movementinformation on the external obstacle 200, which is located in the rearblind spot or the lateral blind spot of the vehicle 100, using a radarsensor 50 installed in the vehicle 100.

The term “radar” is an acronym for “radio detection and ranging”. Theradar sensor 50 is a wireless monitoring apparatus that fires anelectromagnetic wave (millimeter wave) in a band near 24 GHz or 77 GHzto an object and receives the electromagnetic wave reflected from theobject, thereby sensing the distance to the object, the orientation ofthe object, and the altitude of the object.

In an example, the radar sensor 50 is installed on the rear-side portionof the vehicle, and includes a transmitter for generating a radio wave,an antenna (scanner) for radiating the radio wave, a receiver forreceiving the reflected radio wave, and an indicator for displaying animage on a screen. The radio wave generated by the transmitter isusually a millimeter wave. If the radio wave is continuously radiated,it is not possible to know the time point at which the reflected radiowave was fired. Therefore, the radar sensor 50 performs sensing in anintermittent radiation manner of radiating radio waves for a short timeperiod (e.g. 1 to 6 seconds), receiving the radio waves, and then againradiating radio waves. The number of radio waves (millimeter waves) thatare radiated in 1 second is about 1,000, and the propagation speed of amillimeter wave is 300,000 km per second. Based thereon, it is possibleto obtain the distance to a target object by measuring the time takenuntil the reflected wave is received.

The sensor 10 may be connected to the radar sensor 50 installed on therear portion or the side portion of the vehicle 100 in order to sensethe external obstacle 200. The sensor 10 may also sense the externalobstacle 200 using an ultrasonic sensor or a camera sensor, in additionto the radar sensor 50.

The sensor 10 senses the position information on the external obstacle200 through detection points that are sensed.

The electromagnetic wave from the radar sensor 50 is reflected from theexternal obstacle 200, whereby detection points are formed. The sensor10 may sense the external obstacle 200 through the detection points. Thedetection points are continuously formed during the period of radiationof electromagnetic waves from the radar sensor 50, thereby enablingcontinuous sensing of the position information on the external obstacle200.

The determiner 20 forms a predetermined tracking range based on theinitially sensed detection points and determines whether the externalobstacle 200 is a passenger car or a large vehicle based on thedetection points located within the tracking range among the initiallysensed detection points.

As shown in FIG. 6 , the determiner 20 may set a tracking range (gate)based on the detection points of the external obstacle 200 sensed by thesensor 10 in the initial stage, may check the number of detection pointssensed by the radar sensor 50, may determine that the external obstacle200 is a large vehicle when the number of detection points locatedwithin the detection range is greater than or equal to a predeterminednumber, and may determine that the external obstacle 200 is a passengercar or a motorcycle when the number of detection points located withinthe detection range is less than the predetermined number.

The determiner 20 calculates the number of detection points, based onthe information sensed by the sensor 10 and the movement information orposition information on the external obstacle 200, and determines thatthe external obstacle 200 is a large vehicle when the number ofdetection points located within the detection range is greater than orequal to the calculated number of detection points.

The determiner 20 may set the number of detection pointsNumber_(trailer) such that the same is proportional to the sensinginformation (TP: tuning parameter) on the external obstacle 200 sensedby the sensor 10 and is inversely proportional to the positioninformation (ΔR: distance resolution, ΔR_(step): distance step size) andthe movement information (ΔV: speed resolution, ΔV_(step): speed stepsize) on the external obstacle. The number of detection points may becalculated using the following equations.

${Number}_{trailer} = \frac{TP}{\Delta{R \cdot \Delta}V}$${Number}_{trailer} = \frac{TP}{\Delta{R_{step} \cdot \Delta}V_{step}}$

The determiner 20 determines that the external obstacle 200 is a largevehicle when the number of detection points located within the trackingrange is greater than or equal to a predetermined number.

The determiner 20 calculates the number of detection points using theabove equations, checks the number of detection points located withinthe tracking range based on the calculated number of detection points,and determines that the external obstacle 200 is a large vehicle whenthe number of detection points located within the tracking range isgreater than or equal to the calculated number of detection points.

In this way, the determiner 20 may determine whether the externalobstacle 200 is a passenger car or a large vehicle, and the setter 30may set, based on the result of the determination, the rear lateralblind-spot warning range or the rear lateral blind-spot warning time ofthe vehicle 100.

The determiner 20 obtains an individual bit frequency componentproportional to the distance by performing a fast Fourier transform(FFT) operation on the sensing signal of the sensor 10, obtains aDoppler frequency component proportional to the speed by performing theFFT operation on the individual bit frequency component, and calculatesthe average frequency power of the warning region based on the distanceand the speed, determined using the individual bit frequency componentand the Doppler frequency component.

The radar sensor 50 may continuously sense the external obstacle 200 fora certain time period. The waveform of the radar sensor 50 may beconverted into a value in a coordinate plane through the FFT operation.The determiner 20 may obtain an individual bit frequency componentproportional to the distance by performing the FFT operation once on thewaveform of the radar sensor 50, and may obtain a Doppler frequencycomponent proportional to the speed by performing the FFT operationtwice on the waveform of the radar sensor 50, thereby forming acoordinate plane. Thereafter, the determiner 20 may set detection rangesfor a distance region (Rs-Re) and a speed region (Vs-Ve) sensed by thesensor 10.

In this way, the determiner 20 may check and determine the frequencydetection region of the radar sensor 50 in a coordinate plane and maycontinuously check the detection of the external obstacle 200.

When the average frequency power of the warning region is greater thanor equal to a predetermined power value, the determiner 20 determinesthat the external obstacle 200 is a large vehicle.

Upon determining that the average frequency power checked in thedetection range set by the determiner 20 is greater than or equal to thepredetermined power value, the determiner 20 may determine that theexternal obstacle 200 located in the rear blind spot or the lateralblind spot of the vehicle 100 is a large vehicle. The average frequencypower may be continuously checked based on the period of the frequencyof the radar sensor 50.

The average frequency power Pave may be calculated using the followingequation.

$P_{ave} = {\frac{1}{N}\frac{1}{M}{\sum\limits_{i = {Rs}}^{Re}{\sum\limits_{j = {Vs}}^{Ve}P_{i,j}}}}$whereN = Re − Rs + 1, M = Ve − Vs + 1

In this way, it is possible to continuously and accurately determine thetype of external obstacle.

When the determiner 20 determines that the external obstacle 200 is alarge vehicle, the setter 30 increases the rear lateral blind-spotwarning range such that the same is greater than a predetermined range.

When the determiner 20 determines that the external obstacle 200 is alarge vehicle, the setter 30 may increase the rear lateral blind-spotwarning range from a predetermined passenger-car detection range to apredetermined large-vehicle detection range.

Accordingly, when a large vehicle is located in the rear blind spot orthe lateral blind spot of the vehicle 100, the setter 30 sets the rearlateral blind-spot warning range to be increased, and the controller 40controls the rear lateral blind-spot warning operation in response tothe setting of the setter 30, thereby accurately sensing the largevehicle located in the rear blind spot or the lateral blind spot, thusaccurately announcing the result of sensing to the driver.

When the determiner 20 determines that the external obstacle 200 is alarge vehicle, the setter 30 increases the rear lateral blind-spotwarning time such that the same is greater than a predetermined time.

When the determiner 20 determines that the external obstacle 200 is alarge vehicle, the setter 30 may increase the rear lateral blind-spotwarning time from a predetermined passenger-car detection time to apredetermined large-vehicle detection time.

Accordingly, when a large vehicle is located in the rear blind spot orthe lateral blind spot of the vehicle 100, the setter 30 sets the rearlateral blind-spot warning time so as to increase the same, and thecontroller 40 controls the rear lateral blind-spot warning operation inresponse to the setting of the setter 30 such that the rear lateralblind-spot warning operation is performed for a longer time period afterthe large vehicle is sensed, thereby accurately announcing the result ofsensing of the large vehicle located in the rear blind spot or thelateral blind spot to the driver.

FIG. 11 is a flowchart showing a rear lateral blind-spot warning methodof the vehicle 100 according to an embodiment of the present disclosure.

An exemplary embodiment of the rear lateral blind-spot warning method ofthe vehicle 100 according to the present disclosure will be describedbelow with reference to FIG. 11 .

The rear lateral blind-spot warning method of the vehicle 100 accordingto the present disclosure includes a sensing step S10 of sensingposition information and movement information on the external obstacle200, a determination step S11 of determining the type of externalobstacle 200 located in the rear blind spot or the lateral blind spotbased on the position information and the movement information sensed inthe sensing step S10, a setting step S12 of setting a rear lateralblind-spot warning range or a rear lateral blind-spot warning time basedon the type of external obstacle 200 determined in the determinationstep S11, and a control step S13 of controlling the rear lateralblind-spot warning operation based on the rear lateral blind-spotwarning range or the rear lateral blind-spot warning time set in thesetting step S12.

The sensing step S10 includes sensing the position information or themovement information on the external obstacle 200 located in the rearblind spot or the lateral blind spot of the vehicle 100 using the radarsensor 50 installed in the vehicle 100.

In the sensing step S10, the position information on the externalobstacle 200 is sensed through detection points that are sensed.

The determination step S11 includes forming a predetermined trackingrange based on the initially sensed detection points and determiningwhether the external obstacle 200 is a passenger car or a large vehiclebased on the detection points located within the tracking range amongthe initially sensed detection points.

The determination step S11 includes calculating the number of detectionpoints, based on the sensing information and the movement information orposition information on the external obstacle 200 sensed in the sensingstep S10, and determining that the external obstacle 200 is a largevehicle when the number of detection points located within the trackingrange is greater than or equal to the calculated number of detectionpoints.

The determination step S11 includes determining that the externalobstacle 200 is a large vehicle when the number of detection pointslocated within the tracking range is greater than or equal to apredetermined number.

The determination step S11 includes obtaining an individual bitfrequency component proportional to the distance by performing an FFToperation on the sensing signal of the sensor 10, obtaining a Dopplerfrequency component proportional to the speed by performing the FFToperation on the individual bit frequency component, and calculating theaverage frequency power of the warning region based on the distance andthe speed, determined using the individual bit frequency component andthe Doppler frequency component.

The determination step S11 includes determining that the externalobstacle 200 is a large vehicle when the average frequency power of thewarning region is greater than or equal to a predetermined power value.

The setting step S12 includes increasing the rear lateral blind-spotwarning range such that the same is greater than a predetermined rangewhen the external obstacle 200 is determined to be a large vehicle inthe determination step S11.

The setting step S12 includes increasing the rear lateral blind-spotwarning time such that the same is greater than a predetermined timewhen the external obstacle 200 is determined to be a large vehicle inthe determination step S11.

As is apparent from the above description, a rear lateral blind-spotwarning system and method for a vehicle according to the presentdisclosure are capable of recognizing whether an external obstaclelocated in a rear blind spot or a lateral blind spot of a host vehicleis a passenger car or a large vehicle based on detection points or theaverage frequency power of a radar sensor and of, when the externalobstacle is determined to be a large vehicle, controlling a rear lateralblind-spot warning range or a rear lateral blind-spot warning time so asto accurately recognize the position of the large vehicle located in therear blind spot or the lateral blind spot of the host vehicle, therebyaccurately announcing the result of recognition to a driver.

Although exemplary embodiments of the present disclosure have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions, and substitutions arepossible, without departing from the scope and spirit of the disclosureas disclosed in the accompanying claims.

What is claimed is:
 1. A rear lateral blind-spot warning system for avehicle, comprising: a sensor configured to sense position informationand movement information on an external obstacle; a determinerconfigured to determine a type of the external obstacle located in arear blind spot or a lateral blind spot of the vehicle based on theposition information and the movement information sensed by the sensor;a setter configured to set a rear lateral blind-spot warning range or arear lateral blind-spot warning time based on the type of the externalobstacle determined by the determiner; and a controller configured tocontrol a rear lateral blind-spot warning operation based on the rearlateral blind-spot warning range or the rear lateral blind-spot warningtime set by the setter, wherein the sensor senses the positioninformation or the movement information on the external obstacle locatedin the rear blind spot or the lateral blind spot of the vehicle using aradar sensor installed in the vehicle, and wherein the determinerdetermines whether the external obstacle is a large vehicle based on thesensed position information or the movement information.
 2. The rearlateral blind-spot warning system for a vehicle of claim 1, wherein thesensor senses the position information on the external obstacle throughsensed detection points.
 3. The rear lateral blind-spot warning systemfor a vehicle of claim 2, wherein the determiner forms a predeterminedtracking range based on initially sensed detection points and determineswhether the external obstacle is a passenger car or a large vehiclebased on detection points located within the predetermined trackingrange among the initially sensed detection points.
 4. The rear lateralblind-spot warning system for a vehicle of claim 3, wherein thedeterminer calculates a number of detection points based on sensinginformation sensed by the sensor and the movement information or theposition information on the external obstacle, and determines that theexternal obstacle is a large vehicle when a number of the detectionpoints located within the predetermined tracking range is greater thanor equal to the calculated number of detection points.
 5. The rearlateral blind-spot warning system for a vehicle of claim 3, wherein thedeterminer determines that the external obstacle is a large vehicle whena number of the detection points located within the predeterminedtracking range is greater than or equal to a predetermined number. 6.The rear lateral blind-spot warning system for a vehicle of claim 1,wherein the determiner obtains an individual bit frequency componentproportional to a distance by performing an FFT operation on a sensingsignal of the sensor, obtains a Doppler frequency component proportionalto a speed by performing the FFT operation on the individual bitfrequency component, and calculates average frequency power of a warningregion based on the distance and the speed determined using theindividual bit frequency component and the Doppler frequency component.7. The rear lateral blind-spot warning system for a vehicle of claim 6,wherein the determiner determines that the external obstacle is a largevehicle when the average frequency power of the warning region isgreater than or equal to a predetermined power value.
 8. The rearlateral blind-spot warning system for a vehicle of claim 1, wherein,when the determiner determines that the external obstacle is a largevehicle, the setter increases the rear lateral blind-spot warning rangesuch that the rear lateral blind-spot warning range is greater than apredetermined range.
 9. The rear lateral blind-spot warning system for avehicle of claim 1, wherein, when the determiner determines that theexternal obstacle is a large vehicle, the setter increases the rearlateral blind-spot warning time such that the rear lateral blind-spotwarning time is greater than a predetermined time.
 10. A rear lateralblind-spot warning method for a vehicle, comprising: a sensing step ofsensing position information and movement information on an externalobstacle; a determination step of determining a type of the externalobstacle located in a rear blind spot or a lateral blind spot of thevehicle based on the position information and the movement informationsensed in the sensing step; a setting step of setting a rear lateralblind-spot warning range or a rear lateral blind-spot warning time basedon the type of the external obstacle determined in the determinationstep; and a control step of controlling a rear lateral blind-spotwarning operation based on the rear lateral blind-spot warning range orthe rear lateral blind-spot warning time set in the setting step,wherein the sensing step comprises sensing the position information orthe movement information on the external obstacle located in the rearblind spot or the lateral blind spot of the vehicle using a radar sensorinstalled in the vehicle, and wherein the determiner determines whetherthe external obstacle is a large vehicle based on the sensed positioninformation or the movement information.
 11. The rear lateral blind-spotwarning method for a vehicle of claim 10, wherein the sensing stepcomprises sensing the position information on the external obstaclethrough sensed detection points.
 12. The rear lateral blind-spot warningmethod for a vehicle of claim 11, wherein the determination stepcomprises: forming a predetermined tracking range based on initiallysensed detection points; and determining whether the external obstacleis a passenger car or a large vehicle based on detection points locatedwithin the predetermined tracking range among the initially senseddetection points.
 13. The rear lateral blind-spot warning method for avehicle of claim 12, wherein the determination step comprises:calculating a number of detection points, based on sensing informationand the movement information or the position information on the externalobstacle sensed in the sensing step; and determining that the externalobstacle is a large vehicle when a number of the detection pointslocated within the predetermined tracking range is greater than or equalto the calculated number of detection points.
 14. The rear lateralblind-spot warning method for a vehicle of claim 12, wherein thedetermination step comprises determining that the external obstacle is alarge vehicle when a number of the detection points located within thepredetermined tracking range is greater than or equal to a predeterminednumber.
 15. The rear lateral blind-spot warning method for a vehicle ofclaim 10, wherein the determination step comprises: obtaining anindividual bit frequency component proportional to a distance byperforming an FFT operation on a sensing signal of a sensor; obtaining aDoppler frequency component proportional to a speed by performing theFFT operation on the individual bit frequency component; and calculatingaverage frequency power of a warning region based on the distance andthe speed, determined using the individual bit frequency component andthe Doppler frequency component.
 16. The rear lateral blind-spot warningmethod for a vehicle of claim 15, wherein the determination stepcomprises determining that the external obstacle is a large vehicle whenthe average frequency power of the warning region is greater than orequal to a predetermined power value.
 17. The rear lateral blind-spotwarning method for a vehicle of claim 10, wherein the setting stepcomprises increasing the rear lateral blind-spot warning range such thatthe rear lateral blind-spot warning range is greater than apredetermined range when the external obstacle is determined to be alarge vehicle in the determination step.
 18. The rear lateral blind-spotwarning method for a vehicle of claim 10, wherein the setting stepcomprises increasing the rear lateral blind-spot warning time such thatthe rear lateral blind-spot warning time is greater than a predeterminedtime when the external obstacle is determined to be a large vehicle inthe determination step.